Jolt ramming-machine.



E. H. Mun/110110.05011.

R. s. MuMroRn, ExEcuTRlx.

JOLT RAMMING MACHINE.

APPLICATION HLED JUNE 17. 1915.

Patented Feb.15,1916. '5

2 SHEETS-SHEET 2 efk e@ UNTTE sTATEs PATENT OFFICE.

EDGAR H. MUMFORD. VDECEASED. LATE OF PLAITIELD. NEW JERSEY, BY ROSE S.MUMFORD. EXECUTBIX. OF PLAINEIELD. NEW JERSEY.

JOLT RAMMIG-MACHINE.

To IZZ Vwia-0m it may con/lern Be it known that Enma: H. Mt'nronmanduseful Improvements in Jolt Ramming- Machines, of which the following isa specification.

rIhis invention has reference to machines for ramlning sand molds andparticularly to that type of machine known as a jolt rammer in which themoving parts are operated by fluid pressure, the supply of pressurebeing controlled by automatic valve mechanism. One of the chief.objectsofthis invention is to provide a novel and improved form of fluidpressure control valve mechanism which will operate efficiently andaccurately. j The foregoing, together with such other objects as mayhereinafter appear or are incident to the invention are attained bymeans of alconstruction illustrated in preferred form in theaccompanying drawings, wherein- Figure l lis a longitudinal sectionthrough a portion of a combined squeeze and jolt ramming molding machinesuch as shownin' copending application of Edgar H. Mumford, Ser. No.19,931, filed April 8, 1915; Fig..j`2 is a sectioii similar to that ofFig. 1 showingta modification of the improvement; and Fig. 3'is asectional view of another detailed modification of the improvement.

Improvements have been made in jolt ramming apparatus whereby theprovision of n echanical means for positively shifting the valvecontrolling the supply of fluid pressure to the moving parts has beendispensed with, the control of the supply of fluid pressure being -hadthrough the medium of fluid pressure actuated valve mechanism. Theinvention relates more particu- 'larly to an improvement in this latterform of mechanism.

For convenience of. illustration. the invention is shown as applied to acombined sqaeeze and jolt ramming molding machine. Only such parts ofthe apparatus are shown as are necessary to bring out theoperation ofthe improvement. Referring now to Fig. 1, the apparatus comprises a maincasting olitbase 7 which is provided with an annularl'ups'tandingcylindrical portion S and Specication of Letters Patent.

Patented Feb. 15, 1m u.

A Application led .Tune 17. 1915. Serial No. 34.710.

with a centrally disposed cylindrical guide post il. The mold tablesupporting traine is carried on the plunger 11 mounted in thecvlindnhfal portion Si of the base. LThe plunger 11 is hollow and isprovided with a centrally disposed c vlindrical portion 11a whichsurrounds and i's guided by the central guide post 9. The squeezingoperations of' the machine are carried on by the introduction of fluidpressure into the cylinder S beneath the lower face of the plunger 11,but as this forms no part of this invention, further description will bedispensed with.

Referring now to the mechanism for carrying out the jolt rammingoperations, it will be noted that there is a space in the cylinder 11above the post 9 to provide a valve chamber 12, and that a valve block13 is detachably secured by means of the studs 14 to the top of thepost9. The valve block is provided with a passageway for conducti'hg fluidpressure to the interior of the cylinder 11a. such passageway beingcomprised of a horizontally extending inlet passage 15, a horizontallydisposed discharge passage 16 separated horizontally 'by the wall 17,and the passage 18 in the all 17 which serves to connect the passages 15and '16. A vertically movable piston valve A controls the opening 1S.such valve being provided with an upwardly projecting stem 19 which isof such length that it projects slightly above the top face of the valveblock 13 when the valve is in lower or open position. T he lower face ofthe piston portion 20 of the valve is spaced away from the upper face ofthe post 9, for a purpose which will hereinafter appear.

The post 9 has a central chamber 21, from the upper portion of which aninlet port 22 extends to the upper face of the post opening at a pointcommunicating with the downwardly extending end of the passage 15. Fluidpressure is introduced into the chamber 21 through an inlet pipe Q3. thesupply of fluid pressure being controlled by any suitable form of valvemechanism(not shown) in the usual manner. An exhaust port or opening 2iis drilled in the wall of the cylinder 11, andthe valve block at one.end is spaced away from the inner wall of the cylinder 11!l to form aspace 25 with which the port 24 comes into register, as will furtherappear. A restricted passage 15;L extends from the end of the passage 15to the space beneath the lower face of the piston portion 2O of thevalve A.

The operation of the apparatus is as fol lows, assuming that the partsare in the position shown in Fig. 1: F luid pressure is introduced intothe chamber 21l through the supply pipe 23 and passes through the inletport 22 into the passageway 15, thence` through the opening 18 aroundthe valve stein 19 into the discharge passage 16, and thence into thechamber 127 causing the cylinder 11a and the plunger 11 of which thecylinder ormsa part, to rise, carrying the frame l10 upwardly. Duringthis period of operation, the pressures on the opposite4 4faces of thelower portion of the valve A are substantially equalized as it will beseen tha-t the passage 15a permits an accumulation of pressure on thelower face of the piston 2() of the valve. Hoivevei',the pressure on theupper face of the stem 19 of the valve tends to hold the valve oil itsseat. The parts continue their upward movement until the eXu haust port24 in the wall of the cylinder 11a comes into register with the space25, at.

which time the pressure in, the chamber 12 exhausts through lthe port24, thereby causing a -rapid reductionof pressure above' the valve. Thepassage 1G is covered by the rising wall of the cylinder11"L just priorto the uncovering of the port 24.

The pressure accumulated beneath and acting against the lower face ofthe piston portion 2O 'of the valve then immediately causes the valve tomove upwardly to close the valve opening 18, thereby cutting ofi thesupply of fluid pressure from the cha-1nber 21. The plunger '11 andcylinder 11a fall, impacting on the upper face of the base 7. As' thepartsmove downwardly, a tappet 19a in the end of the cylinder 11a cornesinto Contact with the upper end of' the stem 19' of the valve and movesthe valve to open position, after which the operation above described isrepeated, and the rainming oit' the mold effected. v

-Some difiiculty hasbeen encountered in preventing the valve fromprematurely moving upwardly 'to""close the opening 18, which obviouslywould result in an impairment of -the eciency of the device. To overcomethis difficulty, the passage way 15 is formed so as 'to set up apeculiar swirling motion in the air as it flows therethrough, whichcauses the'air to act against the valve to hold'itlin lower or openposition. To impart this swirling motion to the air, the annular wall ofthe passageway 15 is rounded as indicated at 26. It is diicult to defineaccurately just what effect therounding ot the wall'of the passageway 15has on the'air 'assing through the passageway, but it has been found byexperience that the eiect of so' rounding the wall adjacent to the valver.ducted to the lower face of the valve. this form of apparatus, theport 2S is drilled annees passing through the opening 1S to draw thevalve upwardly. This peculiar action ot' the currents of air maybeperhaps best gathered from inspection of Fig. 3.A In the constructiontherein shown, the rounding of the' passageway 15 is accentuated byproviding a downwardly-turned lip 27 on the wall 17l adjacent to theopening 18. The piston portion 20 oi' the valve in this type has a loosetit and pressure accumulates beneath the valve by leakage. 'The valve inintroduced into the valve block from beneath, the plate 28 beingthereafter detachably secured in place.

In F ig. 2 there is shown a slightly modied forni of construction whichdifferentiates from that shown in Fig. 1 in the manner in which thefluid, pressure is conthrough the wall of thep'ost 9 so as tocommunicate with the chamber 21, and a second port 29 located above theport 2S extends in an upward direction trom a point above the port 28opening into the space beneath the lower face of the valve parts.Mounted in the wall ofthe cylinder 11a is a spring-held member 30 havinga groove 31 in its inner face, which groove serves to connect the endsof the ports 28 and 29 after the cylinder 11.a

has moved upwardly a predetermined distance. When these parts arebrought into register, pressure flows from the chamber 21 through theport 28, groove 31 and port 29 to the lower face of the valve, the partsbeing so arranged that they are brought into register substantiallyzgsimultaneously with the uncovering of the exhaust port 24:.

, It will be seen troni-the foregoing that the valve operates with greataccuracy, which results in an increase in eiciency. Furthermore, thearrangement oit' the valve mechanism above the post 9 siinplizlies thewhole structure as it obviatsthe necessity ont forming special openingsor recesses for the introduction ofV the valve parts, and special portswhich otherwise might be nec-- essary The location. of the valve partsabove the post also gives added eiiiciency be cause the valve parts, byreason of their lo cation, are immediately subjected 'to the eii'ects ofchanges inpressure conditions.

1. The combination in a jolt ramlning machine of a-plunger member and acylindrical member, relatively movable and provided with a fluidpressure chamber therebetween, one of said members being provided withan exhaust port, anadmission port for introducing fluid pressure to saidchamber, a valve casing in said chamber, and a valve in said-casing forcontrolling said admission port, said val-ve being fluid pressure heldin open position and being ygoverned as to its closing movement bythesaid exhaustI port when the latter is in registry with the saidchamber.

2. The combination in a jolt ramming machine of a stationary plunger, vavertically movable cylinder mounted thereon, there being a fluidpressure chamber in the cylinder above the plunger and anexhaust port inthe wall of the cylinder and an admission port in the plunger, a valveblock mounted on the plunger andv lying in said chamber and providedwith a passageway in communication with said admission port, and a.fluid pressure actuated valve in said block for controlling saidpassageway normally in open position and governed as to its closingmovement when the exhaust port is brought into registry with the saidchamber.

3. The combination in a jolt ramrning machine of a stationary plunger, avertically movable cylinder mounted thereon, there beinga fluid pressurechamber in the cylinder above the plunger and an exhaust port in thewall of the cylinder and an admission port in the plunger, a valve blockmounted on the plunger and lying in said chamber and provided with apassageway in communication with said admission port, and a fluidpressure actuated valve in said block for controlling said passagewaynormally in open position and governed as to its closing movement whenthe exhaust port is brought into registry with the said chamber, thewallof said passageway being rounded to direct the incomingI current offluid pressure downwardly against the valve.

4. The combination in a jolt ramming machine of a stationary plunger, avertically movable cylinder mounted thereon, there be ing a. fluidpressure chamber in the cylinder above the plunger and an exhaust portin the wall of the cylinder and an admission port in the plunger, avalve block detachably fastened to the top of the plunger and lying insaid chamber and provided with a passageway in communication with saidadmission port, and a fluid pressure actuated valve in said block forcontrolling said passageway normally in open position and governed as toits closing movement when the exhaust port is brought into registry withthe said chamber.

5. The combination in a jolt ramming machine of a cylinder member and aplunger member -relatively movable, means for admitting fluid pressureinto the cylinder member to raise the plunger member comprisingapassageway, and a fluid actuated valve controlling said passageway, thewall of said passageway being formed to direct the incoming current offluid pressure against -a face of the valve to hold it in open position.

6. The combination in a olt ramming machine of a cylinder member and aplunger member relatively movable, one of said members being providedwith an exhaust port, means for admitting fluid pressure into thecylinder member to raise the plunger member comprising a passageway, anda fluid actuated vertically movable valve controlling said passagewayand open when in lower position, the wall of'said passageway beingformed to direct the incoming current of fluid pressure against a faceof the valve to hold it in open position and the valve being governed asto its closing movement by the uncovering of said exhaust port.

In testimony whereof I have hereunto signed my name.

ROSE S. MUMFORD, Eecutrz'a: of Edgar H. Mumford, deceased.

Copiesof thls patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. C.

